Many kinds of such blade supports are known. As a rule, they are used to trim the side edges of endless webs of paper, but they are also used to cut longitudinal perforations into the webs. To do so, the blade supports are clamped to a fastening bar and via the positioning arm, they press with their blade against the endless web, which is guided via a rotating cylinder. Since the blade wears down as the webs are trimmed or perforated, it is interchangeably secured to the blade support device. It has proved to be disadvantageous that the blade can be released from the blade support device only with the aid of a tool. On the one hand, this is inconvenient; on the other, it often cannot be done when there are more than one blade support located close together, because the tool cannot be moved to the blade support device. Moreover, the known blade supports are relatively wide, making the distance between individual perforations or cuts relatively great as well; conversely, with the known blade supports, closely spaced cuts or perforations can be made only if the blade supports are disposed in line with one another rather than side by side. That then requires more than one rotating cylinder, via which the webs to be handled are guided.
Blade supports are known from German Utility Models DE-GM 84 27 036 and DE-GM 91 05 289 and from German Patent Disclosure DE 30 42 472 Al. In the blade support of DE-GM 91 05 289, the blade is supported by a catch element of a quick-action lock, the catch element being supported on a bearing. For play-free support of the blade, the catch element must be adapted to the dimensions of the cutting blade, and the bearing must be adapted to the dimensions of the catch element; this is not only labor- and cost-intensive but often causes malfunctions when the components seize.